The present invention relates to 1,2,3-thiadiazole derivatives and salts thereof, and agrohorticultural disease controller containing said compound as an active ingredient, and method for using the disease controller.
1,2,3-Thiadiazoles are disclosed in JP-A-2-149579/1990 as an agent for treating central nervous system diseases, in JP-A-54-9272/1979, JP-A-3-181463/1991, JA-A-4-234881/1992, Canadian Patent 947297, etc. as a herbicide or a plant growth regulator, and in WO 9501340 and JP-A-7-252242/1995 as a fungicide.
With the aim of creating a novel agrohorticultural disease controller, the present inventors have conducted extensive studies to find that the 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I) or salts thereof which are novel compounds not found in literature are useful as an agrohorticultural disease controller. Based on this finding, the present invention has been accomplished.
The present invention relates to 1,2,3-thiadiazole derivatives represented by the following general formula (I) or salts thereof, an agrohorticultural disease controller containing said compounds as an active ingredient, and a method for using said disease controller: 
wherein R1 represents hydrogen atom, C1-C8 alkyl group, halo C1-C4 alkyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, halo C1-C4 alkyl group, C1-C4 alkoxy group, halo C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different heteroatoms selected from oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups;
A represents a group of the following formula: 
(wherein R2 and R3, same or different, represent hydrogen atom, halogen atom, cyano group, formyl group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, C1-C4 alkylsulfinyl group, C1-C4 alkylsulfonyl group, C1-C4 alkylcarbonyl group, C1-C4 alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, halo C1-C4 alkyl group, C1-C4 alkoxy group, halo C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, C1-C4 alkyl group and C1-C4 alkoxycarbonyl group; further, R2 and R3 may be taken conjointly to form a 3- to 7-membered ring including a C2-C6 alkylene group which may be intercepted by
xe2x80x94Oxe2x80x94,
xe2x80x94S(O)nxe2x80x94 in which n is an integer of 0 to 2,
xe2x80x94COxe2x80x94 or
xe2x80x94NR8xe2x80x94 in which R8 represents hydrogen atom,
formyl group, C1-C8 alkyl group, halo C1-C4 alkyl group, C2-C4 alkenyl group, halo C2-C4 alkenyl group, C2-C4 alkynyl group, halo C2-C4 alkynyl group, C1-C4 alkylthio group, C1-C4 alkylsulfinyl group, C1-C4 alkylsulfonyl group, C1-C4 alkylcarbonyl group, C1-C4 alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl group and phenyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, phenyl C1-C4 alkyl group, substituted phenyl C1-C4 alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group; and said 3- to 7-membered ring may be substituted by one or more same or different substituents selected from the group consisting of halogen atom and C1-C4 alkyl group; and m represents an integer of 0 to 4), or 
in which R2 and R3 are as defined above, or 
in which R2 and R3 are as defined above, or 
in which R2 and R3 are as defined above; and
in the case that m is 0 in the definition of A, B represents cyano group, 5- or 6-membered heterocycle having 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C114 C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different C1-C4 alkyl or phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 C1-C4 alkyl or phenyl groups, carbamoyl C1-C4 alkyl group and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different C1-C4 alkyl or phenyl groups, or
xe2x80x94C(xe2x95x90X) R4
(in which R4 represents hydrogen atom, C1-C8 alkyl group, halo C1-C4 alkyl group, C2-C4 alkenyl group, halo C2-C4 alkenyl group, C2-C4 alkynyl group, halo C2-C4 alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, phenyl C1-C4 alkyl group, substituted phenyl C1-C4 alkyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl group and phenyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl group and phenyl group, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl group and phenyl group, and
X represents O, S,
Nxe2x80x94R6 in which R6 is as defined later,
NOxe2x80x94R6 in which R6 is as defined later,
N(xe2x86x92O)xe2x80x94R6 in which R6 is as defined later,
NN(R6)R7 in which R6 and R7 are as defined later, or
NNxe2x95x90C(R6)R7 (in which R6 and R7, same or different, represent hydrogen atom, halogen atom, formyl group, C1-C4 alkyl group, C2-C4 alkenyl group, C2-C4 alkynyl group, C1-C4 alkylsulfonyl group, halo C1-C4 alkylsulfonyl group, C1-C20 alkylcarbonyl group, C1-C4 alkoxycarbonyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, halo C1-C4 alkyl group, C1-C4 alkoxy group, halo C1-C4 alkoxy group, amino group and C1-C4 alkoxycarbonyl group, phenyl C1-C4 alkyl group, substituted phenyl C1-C4 alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, halo C1-C4 alkyl group, C1-C4 alkoxy group, halo C1-C4 alkoxy group, amino group and C1-C4 alkoxycarbonyl group, phenylcarbonyl group, substituted phenylcarbonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, halo C1-C4 alkyl group, C1-C4 alkoxy group, halo C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl group, phenyl group and substituted phenyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, C1-C4 alkyl group, halo C1-C4 alkyl group, C1C4 alkoxy group and halo C1-C4 alkoxy group, phenylsulfonyl group, substituted phenylsulfonyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, nitro group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, thiocarbamoyl group, substituted thiocarbamoyl group substituted by same or different C1-C4 alkyl or phenyl group, C1-C4 alkoxy carbonimidoyl group, substituted C1-C4 alkoxy carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, C1-C4 alkylthio carbonimidoyl group, substituted C1-C4 alkylthio carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, C1-C4 alkylsulfinyl carbonimidoyl group, substituted C1-C4 alkylsulfinyl carbonimidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, C1-C4 alkylsulfonyl carbonamidoyl group, substituted C1-C4 alkylsulfonyl carbonamidoyl group having, on the nitrogen atom thereof, same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, amidino group, substituted amidino group having same or different substituents selected from the group consisting of C1-C6 alkyl and phenyl groups, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups; and R6 and R7 may be taken conjointly to form a 3- to 7-membered ring including a C2-C6 alkylene group which may be intercepted by
xe2x80x94Oxe2x80x94,
xe2x80x94S(O)nxe2x80x94 in which n is as defined above,
xe2x80x94COxe2x80x94, or
xe2x80x94NR8xe2x80x94 in which R8 is as defined above,
and said 3- to 7-membered ring may have same or different substituents selected from the group consisting of halogen atom and C1-C4 alkyl group)); and
in cases where m is 1 or greater, B represents hydrogen atom, halogen atom, cyano group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 3 same or different substituents selected from the group consisting of halogen atom, hydroxyl group, cyano group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups,
xe2x80x94C(xe2x95x90X)R5
(in which X is as defined above; and R5 represents hydrogen atom, C1-C8 alkyl group, halo C1-C4 alkyl group, C2-C4 alkenyl group, halo C2-C4 alkenyl group, C2-C4 alkynyl group, halo C2-C4 alkynyl group, phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, phenyl C1-C4 alkyl group, substituted phenyl C1-C4 alkyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, 5- to 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups,
Oxe2x80x94R6 in which R6 is as defined above,
S(O)nxe2x80x94R6 in which n and R6 are as defined above, or
N(R6)R7 in which R6 and R7 are as defined above), 
(wherein R5 is as defined above; and R9 and R10, same or different, represent formyl group, C1-C4 alkylcarbonyl group, C1-C4 alkoxycarbonyl group, phenylcarbonyl group, or substituted phenylcarbonyl group having, on the ring thereof, 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group; further, R9 and R10 may be taken conjointly to form a 3- to 7-membered ring including a C2 to C6 alkylene group which may be intercepted by
xe2x80x94Oxe2x80x94,
xe2x80x94S(O)nxe2x80x94 in which n is as defined above,
xe2x80x94COxe2x80x94, or
xe2x80x94N(R8)xe2x80x94 in which R8 is as defined above, and said 3- to 7-membered ring may have one or more same or different substituents selected from the group consisting of halogen atom and C1-C4 alkyl group),
Oxe2x80x94R6 in which R6 is as defined above,
S(O)nxe2x80x94R6 in which R6 and n are as defined above,
N(R6)R7 in which R6 and R7 are as defined above,
Nxe2x95x90C(R6)R7 in which R6 and R7 are as defined above, or
ONxe2x95x90C(R6)R7 in which R6 and R7 are as defined above.
In the definitions of the substituents in the 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I), the term xe2x80x9chalogen atomxe2x80x9d means chlorine atom, bromine atom, iodine atom or fluorine atom; the term xe2x80x9cC1-C8 alkyl groupxe2x80x9d means a straight or branched chain alkyl group having 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like; the term xe2x80x9chalo C1-C4 alkyl groupxe2x80x9d means a straight or branched chain alkyl group having 1 to 4 carbon atoms and substituted by one or more same or different halogen atoms, the term xe2x80x9cC2-C4 alkenyl groupxe2x80x9d means a straight or branched chain alkenyl group having 2 to 4 carbon atoms and a double bond, and the term xe2x80x9chalo C2-C4 alkenyl groupxe2x80x9d means a straight or branched chain alkenyl group having 2 to 4 carbon atoms and substituted by at least one same or different halogen atom.
The term xe2x80x9cC2-C4 alkynyl groupxe2x80x9d means a straight or branched chain alkynyl group having 2 to 4 carbon atoms and a triple bond, the term xe2x80x9chalo C2-C4 alkynyl groupxe2x80x9d means a straight or branched chain alkynyl group having 2 to 4 carbon atoms and substituted by one or more same or different halogen atoms, and the term xe2x80x9c5- or 6-membered heterocycle containing at least one same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atomxe2x80x9d means a 5- or 6-membered ring such as furan, thiophene, pyrrole, oxazole, thiazole, isothiazole, pyrazole, imidazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,2,4-triazole, pyridine, pyridazine, pyrimidine, pyrazine, pyrrolidine, piperidine, morpholine, thiomorpholine, dithiolane, dithiane, piperazine, dioxolane, imidazolidine and the like.
As examples of the salt of 1,2,3-thiadiazole derivative represented by general formula (I), there can be referred to salts of alkali metals such as sodium, potassium and the like, salts of alkaline earth metals such as calcium, magnesium and the like, ammonium salts, substituted ammonium salts substituted by one or more same or different substituents selected from the group consisting of C1-C12 alkyl group, phenyl group, substituted phenyl group, benzyl group or substituted benzyl group, guanidium salt and the like.
As preferred substituents of the present invention, the following are referred to. Thus, as R1, methyl, ethyl, n-propyl, cyclopropyl and the like are preferred. As A, a single bond (B is directly linked to thiadiazole ring) or methylene are preferred. In a case where A is a single bond, B is preferably cyano, formyl, hydroxyiminomethyl, benzyloxyiminomethyl, hydrazonomethyl, phenylhydrazonomethyl, imidazolin-2-yl, 4-methylthiazol-2-yl and the like. In a case where A is methylene, B is preferably chlorine atom, hydroxyl group, methoxy group, benzyloxy group, acetoxy group, benzoyloxy group, ethoxycarbonyloxy group, amino group and hydrochloride thereof, diethylamino group, dipropenylamino group, benzoylamino group, p-toluenesulfonylamino group, 3-phenylureido group, 4-methyl-1,2,3-thiadiazol-5-ylmethoxy group and the like.
The 1,2,3-thiadiazole derivatives of the present invention represented by general formula (I) and salts thereof can be produced, for example, by the Production processes exemplified below. 
wherein R1 is as defined above and R11 represents C1-C8 alkyl group.
A 1,2,3-thiadiazole derivative represented by general formula (I-1) can be produced by reducing a compound of general formula (II) in the presence of a reductant to form a 1,2,3-thiadiazole derivative represented by general formula (I-1) and, after isolating or without isolating the thus formed (I-1), oxidizing (I-1) in the presence of an oxidant.
This reaction can be performed according to the description of Shin Jikken Kagaku Koza, Vol. 15 (II), p. 191 (Maruzen K. K.); Jikken Kagaku Koza (4th edition), Vol. 23(V), p. 43 (Maruzen K. K.), etc. 
wherein R1 and R11 are as defined above, and R4xe2x80x2 represents phenyl group, substituted phenyl group having 1 to 5 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, C1-C4 alkyl group, C1-C4 alkoxy group and C1-C4 alkoxycarbonyl group, 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom, or substituted 5- or 6-membered heterocycle containing 1 to 3 same or different hetero atoms selected from the group consisting of oxygen atom, nitrogen atom and sulfur atom and having 1 to 4 same or different substituents selected from the group consisting of halogen atom, cyano group, hydroxyl group, mercapto group, C1-C4 alkyl group, C1-C4 alkoxy group, C1-C4 alkylthio group, carbonyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, amino group, substituted amino group having 1 or 2 same or different substituents selected from the group consisting C1-C4 alkyl and phenyl groups, carbamoyl group, substituted carbamoyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups.
A 1,2,3-thiadiazole derivative represented by general formula (I-3) can be produced by hydrolyzing a compound of general formula (II) and then reacting it with thionyl chloride to form a compound represented by general formula (III), and after isolating compound (III) or without isolating (III), reacting (III) with a compound of general formula (IV) in the presence of a catalyst.
This reaction can be performed according to the description of xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14(II), p. 794. 
wherein R1, R4 and R6 are as defined above.
A 1,2,3-thiadiazole derivative represented by general formula (I-5) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-4) with a compound represented by general formula (V).
This reaction can be performed according to the description of xe2x80x9cJikken Kagaku Kozaxe2x80x9d (4th edition), Vol. 20 (V), p. 353. 
wherein R1, R4, R6 and R7 are as defined above.
A 1,2,3-thiadiazole derivative represented by general formula (I-6) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-4) with a compound represented by general formula (VI).
This reaction can be performed according to the description of Org. Synth. Coll. VI, p.12 (1988). 
wherein R1 and R6 are as defined above and Hal represents halogen atom.
A 1,2,3-thiadiazole derivative represented by general formula (I-8) or (I-9) can be produced by treating a 1,2,3-thiadiazole derivative represented by general formula (I-1) with a halogenating agent such as thionyl chloride or phosphorus tribromide to form a compound represented by general formula (IIIxe2x80x2), and after isolating the compound (IIIxe2x80x2) or without isolating (IIIxe2x80x2), reacting the compound (IIIxe2x80x2) with sodium formimide and then with an acid such as hydrochloric acid to form a salt of a 1,2,3-thiadiazole derivative represented by general formula (I-7), and then reacting the salt (I-7) with a compound of formula (VII). Further, if a salt of the 1,2,3-thiadiazole derivative of formula (I-7) is reacted with an isocyanate of formula (VIII), a 1,2,3-thiadiazole derivative of general formula (I-8xe2x80x2) can be obtained.
This reaction can be performed according to the description of xe2x80x9cJikken Kagaku Kozaxe2x80x9d (4th edition), Vol. 19 (I), p. 438; Synthesis, 615 (1990); xe2x80x9cJikken Kagaku Kozaxe2x80x9d (4th edition), Vol. 22 (II), p. 1142; xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14 (III), p. 1631; etc. 
wherein R1, R6 and Hal are as defined above.
A 1,2,3-thiadiazole derivative represented by general formula (I-10) can be produced by reacting a 1,2,3-thiadiazole derivative of formula (I-1) with a compound represented by formula (VII) in the presence of a base.
This reaction can be performed according to the description of xe2x80x9cJikken Kagaku Kozaxe2x80x9d (4th edition), Vol. 22 (V), p. 50. 
wherein R1, R6 and Hal are as defined above and nxe2x80x2 represents an integer of 1-2.
A 1,2,3-thiadiazole derivative represented by general formula (I-12) can be produced by reacting a 1,2,3-thiadiazole derivative of general formula (I-1) with a compound represented by general formula (IX) in the presence of a base to form a 1,2,3-thiadiazole derivative represented by general formula (I-11), and after isolating the compound (I-11) or without isolation it, oxidizing the derivative (I-11) in the presence of an oxidant.
This reaction can be performed according to the description of xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14 (III), p. 1716; xe2x80x9cJikken Kagaku Kozaxe2x80x9d (4th edition), Vol. 24 (VI), p. 365; etc. 
wherein R1 and Hal are as defined above; and R2 and R13, same or different, represent C1-C4 alkyl group, carboxyl group, carboxy C1-C4 alkyl group, C1-C4 alkoxycarbonyl group, C1-C4 alkoxycarbonyl C1-C4 alkyl group, carbamoyl group, substituted carbamoyl having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups, carbamoyl C1-C4 alkyl group, and substituted carbamoyl C1-C4 alkyl group having 1 or 2 same or different substituents selected from the group consisting of C1-C4 alkyl and phenyl groups.
A 1,2,3-thiadiazole derivative represented by general formula (I-13) can be produced by reacting a compound represented by general formula (X) with phosphorus pentasulfide and then with a compound represented by general formula (XI).
This reaction can be performed according to the description of xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14 (IV), p. 2198; Org. Synth., Coll. Vol. III, p. 332 (1955); etc. 
wherein R1 is as defined above, R14 represents hydrogen atom or C1-C4 alkyl, and W represents C3-C6 alkylene group which may be substituted by C1-C4 alkyl group and may be intercepted by
xe2x80x94Oxe2x80x94,
xe2x80x94NR6xe2x80x94 in which R6 is as defined above,
xe2x80x94S(O)nxe2x80x94 in which n is as defined above, or
xe2x80x94COxe2x80x94.
A 1,2,3-thiadiazole derivative represented by general formula (I-15) can be produced by subjecting a compound of general formula (X) to a dehydrating reaction to form a 1,2,3-thiadiazole derivative represented by general formula (I-14), and after isolating the derivative (I-14) or without isolating it, reacting the derivative (I-14) with a compound represented by general formula (XII).
This reaction can be performed according to the description of xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14 (II), p. 1190. 
wherein R1, R2, R3 and B are as defined above.
A 1,2,3-thiadiazole derivative represented by general formula (I-17) can be produced by reacting a 1,2,3-thiadiazole derivative represented by general formula (I-16) with a compound represented by formula (XIII) or formula (XIV).
This reaction can be performed according to the description of xe2x80x9cShin Jikken Kagaku Kozaxe2x80x9d, Vol. 14 (I), p. 224; JP-A-7-165757/1995; etc.
The compound of general formula (II) used as a starting compound for production of the 1,2,3-thiadiazine derivative represented by general formula (I) can be produced, for example, by the following method. 
wherein R1 is as defined above, R11 represents C1-C8 alkyl group, and R12 represents C1-C4 alkyl group, C1-C4 alkoxy group or amino group which may have a substituent.
A compound represented by general formula (II) can be produced by reacting a compound represented by general formula (XV) with a compound represented by general formula (XVI) to form a compound represented by general formula (XVII), and after isolating the compound (XVII) or without isolating it, subjecting the compound (XVII) to ring closure using thionyl chloride.
This reaction can be preformed according to the description of J. Am. Chem. Soc., 77, 5359 (1955), etc.
Next, typical examples of the 1,2,3-thiadiazole derivative of the present invention represented by general formula (I) are mentioned below. The invention is by no means limited by these examples.
In Table 1, meaning of the abbreviations are as follows.
Ph: phenyl group
cyclo: alicyclic hydrocarbon
In some of the compounds shown in Table 1, property is expressed by a term of xe2x80x9cPastexe2x80x9d. Table 2 summarizes the data concerning these compounds.
The 1,2,3-thiadiazole derivatives of the general formula (I) or salts thereof according to the present invention are useful for agricultural and horticultural disease control. For example, these compounds have a very high controlling effect against various diseases, for instance, rice blast (Pyricularia oryzae), rice sheath blight (Rhizoctonia solani), rice helminthosporium leaf spot (Cochiobolus miyabeanus), powdery mildew of various host plants such as powdery mildew of barley and wheat (Erysiphe graminis), oats crown rust (Puccinia coronata) and rust of other plants, tomato late blight (Phytophthora infestans) and late blight or Phytophthora rots of other plants, downy mildew of various plants such as cucumber downy mildew (Pseudoperonospora cubensis) and grape downy mildew (Plasmopara viticola), apple scab (Venturia inaequalis), apple alternaria leaf spot (Alternaria mali), pear black spot (Alternaria kikuchiana), citrus melanose (Diaporthe citri), bacterial diseases including Pseudomonas diseases such as cucumber bacterial blight (Pseudomonas syringae pv. lachrymans) and tomato bacterial wilt (Pseudomonas solanacearum), Xanthomonas diseases such as cabbage black rot (Xanthomonas campestris), rice bacterial leaf blight (Xanthomonas oryzae) and citrus canker (Xanthomonas citri) and Erwinia diseases such as cabbage bacterial soft rot (Erwinia carotovora), and viral diseases such as tobacco mosaic (Tobacco mosaic virus).
The agrohorticultural disease controller containing the 1,2,3-thiadiazole derivative of general formula (I) or salts thereof as an active ingredient according to the present invention exhibits a marked controlling effect against the above-exemplified diseases which damage paddy field crops, upland field crops, fruit trees, vegetables, other crop plants, flowers, ornamental plants, and the like. Accordingly, the desired effects of the agrohorticultural disease controller of the present invention can be exhibited by applying the disease controller to the paddy field water, stalks and leaves or soil of the paddy field, upland field, fruit trees, vegetables, other crops, flowers and ornamental plants at a season at which the diseases are expected to occur, either before their occurrence or at the time when their occurrence has been confirmed.
The agrohorticultural disease controller of the present invention is generally put to use after being prepared into a conveniently usable form according to an ordinary manner for preparation of pesticides.
That is, the 1,2,3-thiadiazole derivative represented by the general formula (I) or a salt thereof according to the present invention and, optionally, an adjuvant are blended with an appropriate inert carrier in a proper proportion and dissolved, separated, suspended, mixed, impregnated, adsorbed or stuck, prepared into a suitable preparation form such as suspension, emulsifiable concentrate, soluble concentrate, wettable powder, granule, dust, tablet, etc. and put to use.
The inert carrier used in the present invention may be either solid or liquid. As the material usable as solid carrier, there can be exemplified soybean flour, cereal flour, wood flour, bark flour, saw dust, powdered tobacco stalks, powdered walnut shells, bran, powdered cellulose, extraction residue of vegetables, powdered synthetic polymers of synthetic resins and the like, clays such as kaolin, bentonite, acid clay and the like, talcs such as talc, pyrophyllite and the like, silica materials such as diatomaceous earth, siliceous sand, mica, white carbon (namely, synthetic, high-dispersion silicic acid , also called finely divided hydrated silica or hydrated silicic acid, some of the commercially available products thereof contain calcium silicate as the major component), activated carbon, powdered sulfur, pumice, calcined diatomaceous earth, crushed brick, fly ash, sand, inorganic mineral powders such as calcium carbonate, calcium phosphate and the like, chemical fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride and the like, and compost. These carriers may be used alone or as a mixture thereof.
The material constituting the liquid carrier is selected from materials having a dissolving ability in themselves and materials which have no dissolving ability in themselves but can disperse the active ingredient compound by the aid of an adjuvant. The following are typical examples of the liquid carrier material, which can be used either alone or in the form of a mixture: water; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol and the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone and the like; ethers such as ethyl ether, dioxane, cellosolve, dipropyl ether, tetrahydrofuran and the like; aliphatic hydrocarbons such as kerosene, mineral oils and the like; aromatic hydrocarbons such as benzene, toluene, xylene, solvent naphtha, alkyl-naphthalene and the like; halogenated hydrocarbons such as dichloroethene, chloroform, carbon tetrachloride, chlorobenzene and the like; esters such as ethyl acetate, diisopropyl phthalate, dibutyl phthalate, dioctyl phthalate and the like; amides such as dimethylformamide, diethylformamide, dimethylacetamide and the like; nitrites such as acetonitrile and the like; dimethyl sulfoxide; etc.
As the adjuvant, the following can be referred to as typical ones. These adjuvants are used depending upon purposes, either alone or in combination of two or more in some cases. It is also possible to use no adjuvant at all, in some cases.
A surfactant is used for the purpose of emulsifying, dispersing, solubilizing and/or wetting an active ingredient compound. As the surfactant, there can be exemplified polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene higher fatty acid esters, polyoxyethylene resin acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, alkylarylsulfonates, naphthalenesulfonic acid condensates, ligninsulfonic acid salts, higher alcohol sulfuric esters, etc.
The following adjuvants can also be used for the purpose of stabilizing, tackifying and/or binding the dispersion of active ingredient compound: casein, gelatin, starch, methyl cellulose, carboxymethyl cellulose, gum arabic, polyvinyl alcohol, turpentine, bran oil, bentonite, ligninsulfonic acid salts and the like.
Further, wax, stearic acid salts, alkyl phosphates and the like may be used as an adjuvant for the purpose of improving flowability of a solid product.
Further, naphthalenesulfonic acid condensates, polycondensed phosphoric acid salts and the like may also be used as a peptizer for dispersible products.
Adjuvants such as silicone oils may also be used as a defoaming agent.
The content of the active ingredient compound may be increased or decreased according to the need. For example, in dusts and granules, the suitable content thereof is from 0.01 to 50% by weight. In emulsifiable concentrates and wettable powders, too, the suitable content thereof is from 0.01 to 50% by weight.
For controlling various diseases, the agrohorticultural disease controller of the present invention itself or its appropriate dilution or suspension in water or the like is applied to a crop on which the diseases are expected to occur or a site where occurrence of the diseases is undesirable, in an amount effective for disease control. For example, for controlling the diseases of paddy rice, said disease controller can be used by a method such as direct application to regular paddy field, application to a rice nursery bed, dressing of seeds for direct sowing to flooded paddy field, seed disinfection, etc. For controlling the diseases of barley, wheat, oat or the like, the disease controller of the present invention is applied to stalks and leaves or used for soil treatment where the disease controller is absorbed from the roots.
The application amount of the agrohorticultural disease controller of the present invention may vary depending on various factors including purpose of application, objective disease, state of plant growth, tendency of prevalence of the disease, weather, environmental conditions, preparation form, method of application, site of application, time of application, etc. The application amount, however, should be properly chosen in the range of from 0.1 g to 10 kg per 10 ares as expressed in terms of amount of active ingredient compound, depending on purposes.
In order to expand the spectrum of controllable diseases and the time period of effective application or to reduce the dosage, it is also possible to use the disease controller of the present invention in the form of a mixture with other agrohorticultural disease controllers.